Oh dear, let's hope I can get this right! Most of this stuff is applicable to Vista too by the way, and there is scads of stuff about 64 bit on the MS website.

Win7 64 bit can address far greater amounts of memory in the PC. Think it's 128 gig instead of 4 gig. So if you have the memory, it's much quicker. Programs written for 64 bit are lots faster, but these are not yet the majority. Also, unbelievably, 64 bit Internet Explorer has apparently been deliberately slowed down by Microsoft so that it's not as good as 32 bit IE. I can't see much difference in practice but my internet connection is BT Stone Age anyway.

Security is better - there are features like Kernal Patch Protection which stop malware getting in to the Win7 kernel. Another security measure, years late, is that 64 bit Win7 has mandatory driver signing.

The downside of this is that any 32 bit driver will NOT work. In theory this stops you dead if you have an old printer, scanner, camera etc. However the only problem I have had is our printer (er, 11 years old!)now has to use an MS driver - there is no 64 bit Epson one. This cripples photo printing slightly as you can't download photo paper profiles etc. Realistically though the printer's on borrowed time anyway. I found a nice new Epson scanner driver online which admittedly cost me £8 but this includes improved scanning software so I'm OK with the cost.

Recent 32 bit programs should work OK - there is a 32 bit mode which Windows appears to take care of automatically. I haven't really had a problem yet with legacy programs, but it must be realised that some stuff may not work quite as expected. This may be nowt to do with 64 bit, just obsolescence! You can't expect, for instance, the 16 bit Desert Island screensaver written around 20 years ago, to work 15 years later (shame). In theory I could get most of Office 2000 to work, but since my new Dell has a preloaded starter version of Word, Excel etc on board it's not worth it. I'll probably cough up for Office 2010 eventually.

I suppose what I'm trying to say is go for 64 bit - it is the future. Dell didn't give me any option anyway! Meantime me little Medion netbook chugs away running XP and I intend to keep it that way until I go for an IPad (Pensioner Model).

That's interesting. My biggest problem at the moment is that I can't find out what my present system is running. I went to the Windoze site, and they gave me directaions as to how to check, and I get a nil answer. I assume its because I am running XP Media Version, which isn't mentioned in their instructions.

I've rarely had an issue with running software for 32 bit on my Vista or Win 7 install. The main barrier is how much RAM you have. You can check with Speccy (Look at the amount of RAM. I'd do a screenie but I'm on my netbook which just boots Linux).

I'd go with the 64 bit if you're going to be using it for a while (another 18 months or so). Otherwise you may as well stick with the 32. IMPORTANT: If you do go with 64 bit and there's the option to get 64 bit software from [insert vendor here], DO SO

Do you have a 64 bit CPU? If not, the question is moot. To find more info than you ever wanted to know, click on Start/Accessories/System Tools/System Information (you might need to click on "All Programs" after "Start" if Accessories isn't on your startup screen). If your processor is shown as x86, it's a 32 bit processor. Although MickeySoft did release one 64 bit version of XP, I don't believe XP Media Center was involved.

I've been running Win7 64 bit since I bought a new computer with it installed last fall. I've got mostly praises for it. I've also installed Windows XP Virtual Machine to run some of my old 16 bit programs. So far, I haven't found any 32 bit programs that won't work, although I've had to open the properties screen and change compatibility options for a few of them.

Peripherals may be more of an issue than programs with a 64 bit system. If you've got older peripherals the manufacturers may no longer be updating the drivers for them and you'll be out of luck, except you still may be able to use them with Virtual Machine. I have only a ten year old HP printer attached to my Win7 machine. It works fine, but the automatic duplexer I added on to it isn't even recognized. No biggie for me,since I rarely used it anyway. Manual duplexing was far faster for any big job.

I hate the thought of throwing out old computers, but I don't think I'd bother upgrading an existing computer to Windows 7. I like 64-bit Windows 7, but I find that Ubuntu Linux works very well on older computers. I'd be afraid that Windows 7 would slow down most older computers.Of course, the prices of new computers may be much higher where you live. I can get a fairly good Lenovo Win 7 computer (4 GB RAM, 1 TB HD) here in California for about $425 US. -Joe-